Elemental oxygen occurs predominantly in form of a covalent homodimer on, that is a compound of two O2 atoms and having the empirical formula O2, referred to as molecular oxygen or dioxygen. There is a colorless and odorless gas that is contained in air to 20.942%. It is involved in many combustion and corrosion processes (oxygen for energy).
An older method is based on chemical reactions barium oxide method. It is uneconomical due to high energy costs. For barium oxide is heated under air at 500 degrees C., the barium forms. When heated to 700 degrees C recorded earlier O2 is released by thermolysis again. Prior to development of Linde process, this method was the only way to pure O2 present.
From the Stone Age to Middle Ages, the fire to humans was a phenomenon which has been accepted as a gift from heaven. About the nature of fire caused by the different conceptions natural philosophers of antiquity to alchemist. The fire was seen as an essential ingredient of Earth. In 17th century the notion of a "light mysterious substance" was born. This phlogiston would escape from the burning fuel, heat was understood as a substance. The German-Swedish chemist Carl Wilhelm Scheele conducted experiments. When heating manganese dioxide (manganese dioxide) or potassium permanganate with concentrated sulfuric acid (vitriol) he gave a colorless gas.
Even in so-called main sequence stars like the sun plays a role in energy oxygen. In CNO cycle (CNO cycle) represents O2 is an intermediate of nuclear reaction in which proton capture by a 12C nucleus, which acts as a catalyst, a 4He nucleus (alpha particle) is produced. In extremely heavy stars occurs in late stage of their development to O2 burning, in which the O2 is used as nuclear fuel for reactions that lead to construction of even heavier nuclei.
With the discovery of O2 its meaning was not clear during combustion. The Frenchman Antoine Lavoisier found in his experiments that during combustion does not escape phlogiston, but O2 is bound. By weighing it demonstrated that a substance after combustion was not easier but harder. This was caused by the additional weight of ingested during the combustion process oxygen.
For O2 recovery after Claude process air by means of compressors to 5-6 bar is compressed, cooled and then removed by first filter of carbon dioxide, humidity, and other gases. The compressed air is cooled by flowing past gases from the process to a temperature near the boiling point. It is then expanded in turbines. A portion of energy used for compression can again be recovered. This is the method -. In contrast to Linde process, in which no energy is recovered - a lot more efficient.
The actual separation of nitrogen and O2 by distillation in two distillation columns with different pressures. The distillation is carried out in counter-current principle, that is by the condensation heat of evaporated gas flows upward, condensed liquid drips down. Since O2 has a higher boiling point than nitrogen, it condenses readily and collects at the bottom so, nitrogen at the top of column.
The separation takes place initially at 5-6 bar in so-called medium pressure column. The resulting oxygen-enriched liquid is then (pressure about 0.5 bar) further separated in low pressure column. Through the liquid O2 of low pressure column, gaseous nitrogen of high pressure column is passed. It liquefies this and heated with the votes condensation heat the liquid. The more volatile nitrogen is discharged and preferably remains purified liquid oxygen. This still contains the noble gases krypton and xenon, which are separated in a separate column.
An older method is based on chemical reactions barium oxide method. It is uneconomical due to high energy costs. For barium oxide is heated under air at 500 degrees C., the barium forms. When heated to 700 degrees C recorded earlier O2 is released by thermolysis again. Prior to development of Linde process, this method was the only way to pure O2 present.
From the Stone Age to Middle Ages, the fire to humans was a phenomenon which has been accepted as a gift from heaven. About the nature of fire caused by the different conceptions natural philosophers of antiquity to alchemist. The fire was seen as an essential ingredient of Earth. In 17th century the notion of a "light mysterious substance" was born. This phlogiston would escape from the burning fuel, heat was understood as a substance. The German-Swedish chemist Carl Wilhelm Scheele conducted experiments. When heating manganese dioxide (manganese dioxide) or potassium permanganate with concentrated sulfuric acid (vitriol) he gave a colorless gas.
Even in so-called main sequence stars like the sun plays a role in energy oxygen. In CNO cycle (CNO cycle) represents O2 is an intermediate of nuclear reaction in which proton capture by a 12C nucleus, which acts as a catalyst, a 4He nucleus (alpha particle) is produced. In extremely heavy stars occurs in late stage of their development to O2 burning, in which the O2 is used as nuclear fuel for reactions that lead to construction of even heavier nuclei.
With the discovery of O2 its meaning was not clear during combustion. The Frenchman Antoine Lavoisier found in his experiments that during combustion does not escape phlogiston, but O2 is bound. By weighing it demonstrated that a substance after combustion was not easier but harder. This was caused by the additional weight of ingested during the combustion process oxygen.
For O2 recovery after Claude process air by means of compressors to 5-6 bar is compressed, cooled and then removed by first filter of carbon dioxide, humidity, and other gases. The compressed air is cooled by flowing past gases from the process to a temperature near the boiling point. It is then expanded in turbines. A portion of energy used for compression can again be recovered. This is the method -. In contrast to Linde process, in which no energy is recovered - a lot more efficient.
The actual separation of nitrogen and O2 by distillation in two distillation columns with different pressures. The distillation is carried out in counter-current principle, that is by the condensation heat of evaporated gas flows upward, condensed liquid drips down. Since O2 has a higher boiling point than nitrogen, it condenses readily and collects at the bottom so, nitrogen at the top of column.
The separation takes place initially at 5-6 bar in so-called medium pressure column. The resulting oxygen-enriched liquid is then (pressure about 0.5 bar) further separated in low pressure column. Through the liquid O2 of low pressure column, gaseous nitrogen of high pressure column is passed. It liquefies this and heated with the votes condensation heat the liquid. The more volatile nitrogen is discharged and preferably remains purified liquid oxygen. This still contains the noble gases krypton and xenon, which are separated in a separate column.